After picking image from UIImagePickerController() I try to show a UIAlertViewController() but it does not appear and locks the screen

After as user picks an image from a photo album, they are prompted to enter a value into a UIAlertController. However, the controller doesn't appear and the screen becomes unclickable.

It's strange as I use the exact same code for when a user takes a photo.

The code works when the self.getVal() method is not called. It works as expected. With logging, there are no errors in the code. Basically it's like the AlertController has been created behind the current viewController view. The screen becomes totally unclickable as it's not been dismissed. (That's my two pence)

See code below:

@IBAction func addBarButtonPressed(sender: UIBarButtonItem) {

var alert = UIAlertController(title: "Camera or Existing Photo", message: "Take a photo with the camera, or use an existing photo on your device.", preferredStyle: UIAlertControllerStyle.Alert)